Short answer: Yes. Under New York law, heirs of a deceased sibling who had an ownership interest in real property can and generally must be included in a partition action. The court must make sure everyone with a legal or equitable interest in the property is made a party so it can fairly divide or order sale of the property.

This answer explains how partition actions treat a deceased co-owner under New York law and the practical steps to add heirs or a personal representative as parties to a partition case.

How New York law treats a deceased co-owner in a partition case

Partition law in New York starts with the principle that any person who owns an interest in land may bring an action for partition. The statute that authorizes partition actions is RPAPL §901. See: N.Y. Real Prop. Actions & Proceedings Law § 901. Because the court can only divide or sell what is before it, the court requires that all persons who hold title or an interest in the property be brought into the case.

If a co-owner died before the partition action began (or while it is pending), the decedent’s interest does not disappear. The interest generally passes to the decedent’s estate or heirs (through a will or by intestacy). To resolve the partition, you must bring in either:

• The decedent’s personal representative (executor or administrator) if the estate is opened in Surrogate’s Court; or
• The named heirs or devisees (persons who took by intestacy or under the will), if there is no representative or the estate has been fully administered.

Bringing the correct parties ensures the court can determine the share of the decedent’s interest and distribute proceeds correctly.

Practical steps to add heirs or the decedent’s estate to a partition action in New York

1. Identify whether the decedent’s estate is open. Check Surrogate’s Court records in the county where the decedent lived. If someone has opened probate or administration, that proceeding will name the personal representative (executor or administrator). The New York Courts website has general estate and probate information at: NYCourts — Probate & Estates.
2. If an estate is open: join the personal representative as a party. The representative acts for the estate and can be sued or join the partition action on behalf of the decedent’s interest. You will usually serve the representative with the partition papers and list the estate or representative as a defendant.
3. If no estate is open: identify the heirs or devisees. That means tracing beneficiaries under the will (if any) or heirs-at-law under New York intestacy rules. Once you identify them, name them individually as defendants in the partition complaint and serve them properly.
4. If heirs are unknown or cannot be found: New York practice provides means for substituted or constructive notice in some cases (for example service by publication) and for appointment of a guardian ad litem for infants or incapacitated persons. Courts will allow alternative notice methods when personal service is not possible, but you must follow the CPLR and local rules for notice and service. A title search and genealogical search often help locate heirs.
5. Use amended pleadings or a joinder motion when necessary. If heirs come to light after the complaint is filed, you or the court can add them by amended complaint or by court order joining necessary parties. An attorney will typically prepare and file an amended complaint that names additional defendants and obtains new service where required.
6. Obtain and submit proof of death and representative authority. When adding an estate or representative, file a certified copy of the death certificate and certified letters testamentary or letters of administration (if available) to show the representative’s authority to act for the estate.
7. Address special categories: minors, persons under disability, and missing persons often require the court to appoint a guardian ad litem or to permit special notice procedures before final disposition.

What the court will decide once heirs/estate are parties

When the court has the proper parties, it will:

• determine each party’s legal interest in the property (title, share, liens, or claims);
• decide whether to partition the property in kind (physical division) or by sale and divide the proceeds; and
• order distribution of sale proceeds or conveyances to the parties or the estate in accord with their shares and any liens or expenses of administration.

Failure to join heirs or the estate can later disrupt a partition judgment because someone not made a party could claim an interest and attack the sale or distribution.

Common procedural documents and proof you’ll need

• Death certificate for the decedent.
• Certified letters testamentary or letters of administration (if an estate exists).
• Deed and recent title search showing ownership and chain of title.
• Any will (if available) and court filings from Surrogate’s Court.
• Affidavits of service or proof of publication if some heirs require substituted notice.

Hypothetical example

Suppose three siblings owned a vacation house as tenants in common. One sibling dies without a will. You file a partition action against the two living siblings and the deceased sibling’s interest. You search Surrogate’s Court records and find no opened estate. You identify two adult children who are the decedent’s heirs at law. You amend the complaint to name the two children, serve them, and provide proof of the decedent’s death. If the children cannot agree to a buyout, the court may order a sale and distribute proceeds among the surviving co-owners and the heirs based on their ownership shares.

When to consult an attorney

Adding heirs, locating unknown heirs, using substituted service, and coordinating partition with estate administration can be procedurally complex. An attorney familiar with New York partition practice can:

• search Surrogate’s Court and title records;
• draft amended complaints and notices that comply with CPLR and local rules;
• handle service by publication or guardian ad litem applications; and
• coordinate settlement with the estate’s personal representative.